The disclosure relates to turbomachinery. More particularly, the disclosure relates to ceramic and ceramic matrix composite (CMC) components along the gaspath of turbine sections of such turbomachinery.
CMC has been proposed for wide use in hot sections of gas turbine engines (broadly inclusive of engines used in propulsion via thrust, other propulsive engines, industrial gas turbines, and the like). Particular structures proposed for CMC use include turbine blades and vanes (e.g., United States Patent Application Publication 20100189556A1, Propheter-Hinckley et al., Jul. 29, 2010, “Segmented Ceramic Matrix Composite Turbine Airfoil Component”), combustor components (e.g., United States Patent Application Publication 20170314785A1, Vargas, Nov. 2, 2017, “Ceramic and Ceramic Matrix Composite Attachment Methods and Systems”), and blade outer air seals (BOAS) (e.g., United States Patent Application Publication 20160215645A1, McCaffrey, Jul. 28, 2016, “Blade Outer Air Seal Made of Ceramic Matrix Composite”).
U.S. patent application Ser. No. 15/354,083, Propheter-Hinckley et al., Nov. 17, 2016, “Article Having Ceramic Wall with Flow Turbulators”, (the '083 application), the disclosure of which is incorporated by reference herein as if set forth at length, discloses CMC structures having flow turbulators. For example, an internally-cooled vane is illustrated wherein the CMC forms turbulators as ribs transverse to the cooling flow.
Separately, in the field of metallic blades, U.S. Pat. No. 9,109,452, Martin et al., Aug. 18, 2015, “Vortex generators for improved film effectiveness” discloses ribs along the exterior surface of a blade airfoil interfacing with cooling air from film cooling holes. United States Patent Application Publication 20170234134A1, Bunker, Aug. 17, 2017, “Riblets for a Flowpath Surface of a Turbomachine”, also discloses airfoil surface features.
Also, in the field of blade outer air seals (BOAS), U.S. Pat. No. 7,600,968, Nelson et al., Oct. 13, 2009, “Pattern for the Surface of a Turbine Shroud” discloses various patterns of ribs along the inner diameter (ID) surface of a BOAS.